Control unit



July 2, 1940- H. l.. BOWERS 2,206,475

CONTROL UNIT' Q wuz/M3014 /ffefer l.. 50h/fes July 2, 1940. H. l.. BOWERS V coN'rnoL `UNI-'r Filed Feb. 17, 1939 2 snetsfsheet 2 JWQW v#5612567 l 50u/EBS Patented July 2, 1940 CONTROL Um'r Herbert L. Bowers,l Kenmore, N. Y., assigner to Bell Aircraft Corporation, Buffalo, N. Y., a corporation of New York Application February 1.7, 1939, Serial No. 257,012

5 Claims.

This invention relates to control devices, and more especially to a unit which may be mounted in a control surface of an airplane and which is designed to operate the trimming tab attached to the said control surface.

One of the objects of my invention is to provide a. control unit which is mounted in a control surface of an airplane and which is so designed that, by its operation, angular motion can be transmitted to a trimming tab pivotally mounted on said control surface.

Still another object of my invention is to provide a control unit which is sumciently compact in construction and lightin structure to permit it to be' mounted within the control surface of an airplane.

A further object of my invention is to provide a control unit to operate a trimming tab, said-control unit being irreversible in action in order to eliminate flutter in the trimming tab.

With these and other objects in view, my invention embraces the concept of providing a control unit which is so constructed that it may be mounted in a control surface of an airplane without interfering with the eiiicient operation of the said control surface. sists of a housing in which is rotatably mounted an expansible unit which consists of a sleeve having internally threaded extremities which form a connection between two tubular members, each of which has an externally threaded portion.

The parts of the expansible unit arev threaded in such a manner' that a movement of the threaded hub of the sprocket will cause the tubular members to either telescope or move in opposite directions. The movement of the tubular members relative to each other is transmitted to the trimming tab by means of cables which are attached to the unthreaded ends of the tubular members.

While for purposes of illustration I have shown the control unit, which forms the subject of this invention, mounted in one of the elevators of an airplane and operatively attached to one of the trimming tabs, it is intended that a similar unit be mounted on the elevator which forms the opposite side of the empennage. In this manner the trimming tabs mounted on each of the stabilizers may be operated by means of separate units.

Moreover, although I have shown my control unit mounted in an elevator, it is obvious that it may be mounted in the rudder or ailerons of the airplane and operatively connected to the trimming tabs attached to these control surfaces.

My control unit con- In the drawings:

Figure 1 is a view in side elevation showing mycontrol unit mounted on a beam of an elevator control.

Figure 2 is a top plan view of the arrangement shown in Figure 1.

Figure 3 is a view taken along line 9-3 of Figure 2 looking in the direction of the arrows.

Figure 4 is a view taken along line 4-4 of Figure 3 looking in the direction of the arrows.

Figure 5 is a view taken along line 5`5 of Figure 3 looking in the direction of the arrows.

Figure 6 is a view taken along line 6 6 of Figure 3 looking in the direction of the arrows.

For purposes of illustration I have shown my control unit, which is generally designated by the numeral I, mounted in operative position upon the cross beam 2 of an elevator 3. The elevator 3 is pivotally mounted onv the stabilizer 4 of an airplane, as indicated at 5, and is provided with a trimming tab 6 which is pivotally mountedon the elevator 3 by means of suitable hinges, one o! which is indicated at 1.

While I have only shovm one of my control units, it is intended that a similar unit be mounted in the elevator which is situated on the opposite side of the empennage of the airplane. As best shown in Figure 3, the control unit I is provided with a` divided cylindrical housing 8 which comprises a rearwardly projecting portion 9 and a forwardly projecting portion I0, the open end of which is closed by a cap II. The forward end oi' the portion I0 is provided with a centrally located aperture I2 and its opposite end is formed with a spigot I3. 'Ihis spigot I3 is adapted to engage a socket I3' situated on the forward end of the portion 9 in such a manner as to form an aligning t when the two portions are joined.

. 'I'he portion 9 of the housing 8 is stepped, and its lower end, which is adjacent the portion IIJ, is provided with peripheral apertures I4. 'I'he re duced end of the portion 9 is provided with a cen,- trally located aperture I5 which is in line with the aperture I2 in the forward portion I0. They portion 9 is anged, as at 9', to provide means for attaching the unit I to the beam 2 of the control surface 3.

Contained within the housing 8 is an expansible structure which comprises a pair of telescoping tubular members I6 and I1 which are in screw-threaded engagement with a rotatable sleeve I8 which is provided with an integral sprocket I9. 'I'he outer ends 20 of each of the tubular members I6 and I1 are provided with diametrically opposed fiat ends 2I and pass through the apertures I2 and I5, respectively. The apertures I2 and I 5 are formed to correspond with the cross-sectional contour of the ends 21| of the tubular members I6 and I1 to permit only linear movement of these tubular members -I8` and I1. The inner ends of the member I1 and the intermedatepcrtion of the member I6 are externally threaded opposite the disposed screw threads 22 and .23, respectively. These screwthreads engage internal threads 2| and 25 formed in the sleeve I8. The opposite ends of the sleeve I8 carry anti-friction bearings 2l which are in turn carried by the housing 8.

The sprocket I9 engages a chain 21, the free ends of which are attached to cablesv 2 8 which extend to an operating device which is vnot shown, but which may be located .conveniently for useof the pilot.

By means of this construction, rotary movement of the sleeve I3 through the cables 28, chain 21 and sprocket I9 will impart linear movement to the tubular members I3 and I1. This movement will cause the membersA either to separate or telescope. This action, however, is not reversible. In other words, linear movement'of the tubular members cannot be transferred to rotary movement of the sleeve I8.

The control unit I is operatively connected to the trimming tab 6 by means of a iexible cable 30. One end of this cable 30 is connected to the projecting end of the tubular member I1 by. means of a shackle 3I. The cable end passes over a spool 32 located on the hinge line of thetrimming tab 6 and under a clamping bolt .33 positioned rearwardly of the spool 32. After passing around the bolt 33, the cable passes under the spool 32 and extends forwardly and through the tubular members I3 'and I1 where it is attached to an adjustable yoke 34. 'I'he yoke 34 is dadjustablv attached to an end plate 35 screwed to the projecting end of the membe I6 by means of a bolt 38. j

By means of this connection, the trimming tab 8 may be raised or lowered by the tension to which the cable 30 is subjected because of the linear movement of the tubular members Il and I1. Moreover, by this construction proper operating tension is given to vthe cable 30 to prevent fiutter of the trimming tab 8 when it is in its normal or zero position.

While for purposes of illustration I have'de-j scribed one form of my control unit, it is obvious that the form can be varied "or mechanical equivalents substituted without departing fromA the spirit of this invention. I wish it understood. therefore, that I intend that this invention be only limited by the prior art and the scope o! the appended claims.

I claim:

- l. In a device for governing the movement of` a control surface of an airplane, a control de' .surface by means .ofconnecting lin accent 2. In a device for governing the movement of a control surface .of an airplane, a control device mounted within an airfoil of the airplane, said control device being connected to the said control comprising a rotatably mounted sleeve the extremities of which are internally threaded, a device mounted on the sleeve by meansof which it can be rotated, and a pair of tubular members coaxially aligned, each of said tubular members .being provided with an externally threaded portion and each of said threaded portions .being adapted to engage one of the .threaded extremities of the sleeve, whereby a motion oi the sleeve in one direction will cause the tubular membersto telescope .and a movement of the sleeve in the other direction will cause the members to separate, one of the said connecting links being attached directly to-one of the tubular members and the other connecting link passing through both of the tubular members and being attached to the remaining tubular' member, whereby a rotative movement of the sleeve will impart a lineal movement`v to the tubular members which results in -a selective movement of the control surface.

3. In' a device for governing the movement of a control 'surface of an airplane, a control device mounted within an airfoil of the airplane, said control device being connected to the .said control surface by means ofconnecting links, comprising a rotatably mounted sleeve the extremities of whichare internally threaded, a device mounted onthe. sleeve by means of which it can be rotated, and a 'pair of tubular members coaxiai-ly aligned, each of saidtubular members being provided-with an externally threaded portion and each of said vthreaded portions being adapted -to engage one of the'thre'aded extremities of the sleeve, whereby a motion of the sleeve in one direction will cause the tubular members to telescope and a movement of the' sleeve in the other direction will cause the members to separate, one of said connectinglinks being attached directly to the yextremity of the-exteriorly disposed tubular y member and .the other 'passing through both tubular members and being attached to the inwardly disposed tubular "member, whereby a rotative movement of .the sleeve will impart a linealmovement to; the-tubular members which-resultsin a' selective movement ofthe control surface.

`4. In a device'for governing the movement of acontrol surface of an airplane, a control-device. mounted within an airfoil oi' the airplane,said.

ofy the outer of the two tubular members and a threaded portion on the exterior of the inner tubular member adjacent its center portion, saidvl threaded portions on the two members being oppositely disposed and each being adapted to engage one of the threaded extremities of the hub, one of said links being attached to the unthreaded extremity 'of the exteriorly disposed tubular lar members and 'being attached to the extremity of the interiorly disposed tubular member at the point furthest removed from the other member, whereby the rotative movement of the sleeve' imparts a lineal movement to the tubular mem bers which results in a selective movement'of the control surface.

5. In a device for governing the movement of a control surface of an airplane, a control device mounted within an airfoil of -the airplane, said control device being connected to the said control surface by means of connecting links, comprising a housing provided with peripherally disposed apertures, a sleeve rotatably mountedwithin the housing on bearings which are carried by the housing, said sleeve being com-posed of a hub, a sprocket concentrically mounted on the hub, said sprocket being provided with teeth which are aligned with said apertures, a chain for operating the said sleeve carried by the teeth; and a pair of members which are coaxially aligned, a threaded portion on the exterior of the extremity o! the exteriorly disposed member and a threaded portion on the exterior of the interiorly ldisposed member adjacent its center portion, said threaded portions being oppositely disposed and each of said threaded portions being adapted to engage one of the threaded extremities of the hub, whereby rotative movement of the sleeve will cause a`linea1 movement of the tubular members, apertures in the housing through which the opposed extremities of the tubular members extend, one oi.' said links being attached directly to the extremity of the exteriorly disposed tubular member and the other passing through both of the tubular members and being attached to the interiorly disposed tubular member, whereby a rotative movement of they sleeve will impart a lineal movement to the tubular members which results in a selective movement of the control surface. f

HERBERT L. BOWERS. 

